The two biggest shareholders in China Aircraft Leasing Group Holding Ltd (CALC) said on Monday they had no plans to cut their stake in the firm after it revealed it was unable to contact its founder and chief executive, who resigned without explanation.

Shares in CALC, Asia’s only listed aircraft lessor, plunged by nearly a fifth on Friday to a record low after it said CEO Poon Ho Man had quit while on leave, spooking investors in a country where senior executives have in the past vanished or quit suddenly, leaving shareholders in the lurch.

Poon’s disappearance also coincided with media reports that linked him to a government probe into possible corruption at one of the company’s clients, China Southern Airlines, which in January said its executives were under investigation for “job-related crimes”.